Sj. Walker et al., DESIGN AND FABRICATION OF HIGH-EFFICIENCY BEAM-SPLITTERS AND BEAM DEFLECTORS FOR INTEGRATED PLANAR MICROOPTIC SYSTEMS, Applied optics, 32(14), 1993, pp. 2494-2501
High-frequency gratings with rectangular-groove profiles are used to g
enerate high-efficiency beam splitters and beam deflectors. The effect
s of the grating design parameters, i.e., period, groove depth, duty c
ycle, number of phase levels, and polarization state (TE and TM) of th
e incoming signal, are considered. The case of the binary beam splitte
r grating is analyzed by using rigorous electromagnetic grating analys
is. Fabrication techniques are presented in which three different lith
ographic techniques are considered (optical contact, deep-UV stepper r
eduction, and electron-beam direct write). Experimental results of 97%
efficiency for the beam splitter grating and up to 80% for the beam d
eflector grating are reported.